The present invention relates to circuit device for switching the high/low beam lamp; and particularly to circuit device for sustaining the illumination of a vehicle used high illumination discharged (HID) lamps.
The prior art head light has a bulb having two tungsten silks. The tungsten silks can be used to emit a high beam and a low beam, respectively. However, with the advance of technology, some novel light source has been developed, such as high illumination discharged (HID) lamp tube which is used to replace the conventional tungsten bulb. The HID lamp has an illumination better than the current used tungsten bulb and is a single light source. Therefore, the HID lamp can not have two light sources in one lamp tube. As it is used as a vehicle lamp as a head lamp. Two HID lamps are necessary, one as a high beam light and the other as a low beam light. However, this will increase the cost, and moreover, for prior vehicle installed with two light source bulb, the HID lamps can not be used since this kind of prior art vehicle has only one lamp seat.
Moreover, the prior art tungsten lamps is controlled by two ways of positive polarity and negative polarity. Since three terminals of the tungsten lamps are isolated from one another, and thus no problem of the continuity of positive polarity and negative polarity. As HID lamps are used as head lamps of a vehicle, the control way of positive polarity and negative polarity must be overcome since the HID lamps are driven by electronic ballasts. In switching the polarities, the current flowing to the electronic ballasts will interrupt so as to induce a flash effect of the electronic ballast. This will reduce the lifetime of the electronic ballasts and the HID lamps.
Accordingly, the primary object of the present invention is to provide a circuit device for sustaining the illumination of a vehicle used high illumination discharged (HID) lamp so as to prolong the lifetime of the electronic ballasts and HID lamps.
To achieve above mentioned object, the present invention provides a circuit device for sustaining the illumination of a vehicle used high illumination discharged (HID) lamp. The circuit device comprises: a high/low beam switching-delay circuit, and an HID lamp set power supply circuit. The high/low beam lamp switching delay circuit includes a lamp switch for switching the high/low beam lamps of a vehicle; a polarity correction circuit for inducing current of correct positive or negative polarities to flow to the time delay circuit; a time delay circuit having a capacitor for storing charges of the current from the polarity correction circuit; an isolation circuit having an optical coupler. The HID lamp set power supply circuit includes an isolation circuit having a signal receiving end for receiving signal coupled from the optical coupler; a large current conduction circuit having a relay for controlling the operations of an electronic ballast and a low beam lamp; a battery; an HID lamp circuit serves for actuating the electronic ballasts at two lateral sides of said vehicle and an HID lamp.
By above mentioned circuit device, when the lamp switch switches between high/low beam lamps of a vehicle, the low lamp beam is sustained to light up continuously, thereby, the lifetimes of the electronic ballasts and HIV lamp are prolonged.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing.